Remember, CBs are an affront to God and should never be used for off road vehicles. If you are a member of a club that uses CBs and will not budge to at least convert to GMRS, join a new club.
In a perfect world, y'all would at least get a Amateur Technician license and maybe a few of the more committed of you could get a General. I am in the middle of trying to convert a few clubs I am involved in to go to Amateur radio right now. One I am having a slow but sure success with, the "Jeep-centric" one is more hell-bent on keeping their CBs, no matter how many rides we go on where at least 30% of them have faulty equipment and half of the radio chatter is faint calls of "Can anyone hear me?"
On the group that I am having a bit of success with (coincidentally, mostly Toyotas) I got on of my local radio clubs to "test" a new instructional curriculum on people in the overland club. I got quite a few guys licensed there and once non-licensed people start seeing their friends Ham gear and what it can do and see the study guides and how it really isn't that difficult, they start doing it on their own one-by-one. One of our most recent members got his Tech Ticket on his own and then drove to the Ham Radio Online store in Atlanta a few hours away right after and bought a brand new Icom ID-5100 and a bunch of stuff to go with it.
As far as cost goes, that is like asking "How much does it cost to get into 4x4 stuff?" Well, will you be happy with an older, used 4Runner with 200,000 miles for 5 grand or do you prefer a brand new Jeep Wrangler Unlimited Rubicon for 45 grand? Identify your needs and what you are going to use it for. Do you need a rig that can do HF, VHF, UHF, SSB, CW, RTTY, FM, AM, Digital, etc... for $920
https://www.hamradio.com/detail.cfm?pid=H0-011766 Do you need a high quality, reliable VHF FM radio that is reasonably priced at $127
https://www.hamradio.com/detail.cfm?pid=H0-014764
The beauty of Amateur radio is that there is a HUGE selection of radios and capabilities out there to tailor to your needs whereas the GMRS market is a bit limited right now. For example, I have this Kenwood TM-V71A in my 4x4.
https://www.hamradio.com/detail.cfm?pid=H0-008951 and I have a friend with the above mentioned Icom ID-5100.
https://www.hamradio.com/detail.cfm?pid=H0-014084
Both radios have 2 VFOs, or 2 separate radios units inside that can transmit and listen on UHF and VHF in addition to scanning. So, one of use can be the lead vehicle and the other can be the trail vehicle and in the even that the group breaks up into 2 smaller groups or simplex comms are unreliable, he and I can both be on our simplex frequency in addition to being on a local repeater.
In addition, if someone like myself that has a General or Extra license, we could along a portable/mobile HF radio such as this
https://www.hamradio.com/detail.cfm?pid=71-002216 and a buddipole antenna or a field expedient antenna kit and be able to reach the rest of the world if really, really needed.
I do want to clarify, everything that was stated regarding GMRS is true and GMRS is a good radio solution, has its place and should be considered. As a matter of fact, I intend on getting a GMRS license in the near future so I can pop a few mobiles in the family vehicle on account that literally nobody else in my entire family has any interest in getting their Tech license. Also, all of your family can operate under your GMRS license whereas with an Amateur license only you can or someone else with your direct presence and supervision.